Garmin GPS - Unit that records tracks with elevation

Author

Unit that records tracks with elevation

Bob Bailey

2007-09-20, 10:33 pm

I'm pretty much convinced that my nuvi 350 will not do this. So, I'll
get a second unit that is focused on this task:
- record tracks automagically
- high granularity, ie, 10-20 feet?
- elevations of 10-20 feet resolution

Other considerations:
- cheap, since it's second unit, single purpose
- long battery life
- topo map capable
- PC comm capable
- will work on trails

Any suggestions?

tia... Bob

TeddyBare

2007-09-21, 10:33 am

"Bob Bailey" < bobat@messagebuilder
sdot.com> wrote in message
news:ZOGdnaK9Ds9Aum7
bnZ2dnUVZ_o-mnZ2d@rcn.net...
> I'm pretty much convinced that my nuvi 350 will not do this. So, I'll get
> a second unit that is focused on this task:
> - record tracks automagically
> - high granularity, ie, 10-20 feet?
> - elevations of 10-20 feet resolution
>
> Other considerations:
> - cheap, since it's second unit, single purpose
> - long battery life
> - topo map capable
> - PC comm capable
> - will work on trails
>
> Any suggestions?
>
> tia... Bob

Dan Anderson

2007-09-21, 10:33 am

Bob Bailey wrote:
> I'm pretty much convinced that my nuvi 350 will not do this. So, I'll
> get a second unit that is focused on this task:
> - record tracks automagically
> - high granularity, ie, 10-20 feet?
> - elevations of 10-20 feet resolution
>
> Other considerations:
> - cheap, since it's second unit, single purpose
> - long battery life
> - topo map capable
> - PC comm capable
> - will work on trails
>
> Any suggestions?

I'm currently using a Garmin 76Cx, 76S, and a Vista HCx to record trails. Before
you get a model with an "H", meaning it has the MediaTek chipset, you might look
at the following:

http://www.gpsmap.net/ CompareHikes...76
S.html

A 60Cx, 76Cx, or with an "S" has the SiRF III chipset. This chipset picks up
very weak signals so can do very well in forests/tree cover. If you are in a
canyon with a poor satellite constellation, it can pick up reflected signals
that will throw the position off - I've had the 76S record the trail more
accurately than the 76Cx under that type of condition.

If the view of satellites is limited by terrain, the GPS elevation can get way
off. My averaging software dumps records where the elevation range is greater
than 200 ft. I've seen it get into the 400 ft. range. To smooth out the GPS
elevation, you might consider a model with a barometric altimeter (an "S" model
or a Vista).

Firmware version 2.7 of the Vista Cx has a position bug. If Garmin doesn't fix
it you would be stuck with 2.6 unless you don't mind having tracks shifted by 20
to 50 ft. from where it should be.

Some models to consider: 60Cx or 76Cx and with an "S" if you want cleaner
elevations.
An older version such as the GPSmap 76 or GPSmap 76S if you don't mind the more
limited memory and if the tree cover isn't too thick. An external antenna helps
a little. {Short battery life - new units for long battery life}.

Possible disadvantage of the "S" models: I run them with auto calibration to
compensate for weather changes. I think the algorithm can delay getting to the
correct elevation when you change elevation rapidly. In other words, I calibrate
the elevation to the current/correct elevation, drive to the trailhead, check
the elevation and the sensor models are too low by perhaps 100 ft. and also
lower than the current GPS elevation. I've seen it when I've gone up or down a
steep hill but doesn't always happen. If you don't have steep hills, you will
probably be okay.

Seems to me you have already bought MapSource Topo 2008 so that would be another
reason to look at Garmin handheld models. Look under the outdoor section on
Garmin's web page.

--
Dan
(email change 2001 to 2004)
(www.gpsmap.net)

Bob Bailey

2007-09-21, 3:33 pm

Dan Anderson wrote:
> Bob Bailey wrote:
>
>
> I'm currently using a Garmin 76Cx, 76S, and a Vista HCx to record
> trails. Before you get a model with an "H", meaning it has the MediaTek
> chipset, you might look at the following:
>
> http://www.gpsmap.net/ CompareHikes...76
S.html
>
> A 60Cx, 76Cx, or with an "S" has the SiRF III chipset. This chipset
> picks up very weak signals so can do very well in forests/tree cover. If
> you are in a canyon with a poor satellite constellation, it can pick up
> reflected signals that will throw the position off - I've had the 76S
> record the trail more accurately than the 76Cx under that type of
> condition.
>
> If the view of satellites is limited by terrain, the GPS elevation can
> get way off. My averaging software dumps records where the elevation
> range is greater than 200 ft. I've seen it get into the 400 ft. range.
> To smooth out the GPS elevation, you might consider a model with a
> barometric altimeter (an "S" model or a Vista).
>
> Firmware version 2.7 of the Vista Cx has a position bug. If Garmin
> doesn't fix it you would be stuck with 2.6 unless you don't mind having
> tracks shifted by 20 to 50 ft. from where it should be.
>
> Some models to consider: 60Cx or 76Cx and with an "S" if you want
> cleaner elevations.
> An older version such as the GPSmap 76 or GPSmap 76S if you don't mind
> the more limited memory and if the tree cover isn't too thick. An
> external antenna helps a little. {Short battery life - new units for
> long battery life}.
>
> Possible disadvantage of the "S" models: I run them with auto
> calibration to compensate for weather changes. I think the algorithm can
> delay getting to the correct elevation when you change elevation
> rapidly. In other words, I calibrate the elevation to the
> current/correct elevation, drive to the trailhead, check the elevation
> and the sensor models are too low by perhaps 100 ft. and also lower than
> the current GPS elevation. I've seen it when I've gone up or down a
> steep hill but doesn't always happen. If you don't have steep hills, you
> will probably be okay.
>
> Seems to me you have already bought MapSource Topo 2008 so that would be
> another reason to look at Garmin handheld models. Look under the outdoor
> section on Garmin's web page.
>

Dan, Thanks so much for reposting.

Bob Bailey

2007-09-21, 10:33 pm

Jack Erbes

2007-09-21, 10:33 pm

Bob Bailey wrote:
<snip>
> I'm a bit confused: Do I have to have a unit with an altimeter to record
> tracks with elevation data? The unit does "know" what its current
> elevation is but will it record that in the track.

The only units with barometers are the 60CSx and 76CSx. They use that
for the elevation and will record the barometric altitude in tracks
(both saved tracks and tracks logged to the data card).

The units without a barometer (altimeter) record the elevation
calculated by the GPS receiver instead of the barometric altitude. The
GPS calculated elevation is generally quite a bit less accurate than the
barometric.

Jack

Dan Anderson

2007-09-22, 10:33 pm

Jack Erbes wrote:
> Bob Bailey wrote:
> <snip>
>
> The only units with barometers are the 60CSx and 76CSx. They use that
> for the elevation and will record the barometric altitude in tracks
> (both saved tracks and tracks logged to the data card).
>
> The units without a barometer (altimeter) record the elevation
> calculated by the GPS receiver instead of the barometric altitude. The
> GPS calculated elevation is generally quite a bit less accurate than the
> barometric.

The Vista also has a barometric altimeter. The "Vista" in the
eTrex series is the equivalent of the "S" in the numbered
models. The "Legend" is the equivalent of the numbered
models without the "S". The GPSmap 76 is to the Legend
as the GPSmap 76S is to the Vista.

All Garmin handhelds since the eTrex record the
elevation in the waypoint and tracklog. The early basic
Geko (100?) may be an exception (I don't know the Gekos very
well - more sophisticated Gekos do). The 1990's model 12 series
did NOT record the elevations.

--
Dan
(email change 2001 to 2004)
(www.gpsmap.net)

Jack Erbes

2007-09-23, 7:33 am

Dan Anderson wrote:
<snip>

> The Vista also has a barometric altimeter. The "Vista" in the
> eTrex series is the equivalent of the "S" in the numbered
> models. The "Legend" is the equivalent of the numbered
> models without the "S". The GPSmap 76 is to the Legend
> as the GPSmap 76S is to the Vista.
>

Oops, another boo boo on my part. Thanks for correcting me on that, Dan.

My 76Cx was my first Garmin handheld and I've never noticed that that
the Vistas had the barometer too. It seems like Garmin would have used
the "S" in all the models with barometers to make it less confusing or
simpler to understand.

I don't consider myself ready for the final exam on Garmin models and
trivia yet but I think I should have noticed that. :> )

Maybe my ignorance can be attributed to the pile of little used
Magellans over in the corner...

Jack

Dan Anderson

2007-09-23, 12:33 pm

Jack Erbes wrote:
> My 76Cx was my first Garmin handheld and I've never noticed that that
> the Vistas had the barometer too. It seems like Garmin would have used
> the "S" in all the models with barometers to make it less confusing or
> simpler to understand.

Less confusing?!?!?!? ** smile-wink **

It seems like there were two different design teams, one for the
eTrex series and another for what I tend to think of as the mainstream
models. The eTrex team may have had the goal to develop receivers
with a different look and feel than the other models and prior models.

> I don't consider myself ready for the final exam on Garmin models and
> trivia yet but I think I should have noticed that. :> )

When I say "handhelds" I need to remember that there are Gekos
and other less commonly used models that I don't know that well.
Other models don't necessarily have some of the common features
that the models we are usually using and talking about.

> Maybe my ignorance can be attributed to the pile of little used
> Magellans over in the corner...

I'm sure that makes a difference. I looked at a surplus Magellan
in the early 90's and some Lowrance. Then I spotted a Garmin 38
and bought it. So it has been Garmin since for me.

--
Dan
(email change 2001 to 2004)
(www.gpsmap.net)

LinkBot